- An activated catalyst RhH(PPh3)4-dppe-Me 2S2 for α-methylthiolaton of α-phenyl ketones
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In the presence of catalytic amounts of RhH(PPh3)4, 1,2-bis(diphenylphosphino)ethane (dppe), and dimethyl disulfide, cyclic and acyclic α-phenyl ketones reacted with p-cyano-α- methylthioacetophenone giving α-methylthio-α-phenylketones. The activated catalyst containing dimethyl disulfide was effective for the α-methylthiolation reaction of these less reactive substrates.
- Arisawa, Mieko,Toriyama, Fumihiko,Yamaguchi, Masahiko
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scheme or table
p. 18 - 23
(2011/10/09)
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- Rhodium-catalyzed phenylthiolation reaction of heteroaromatic compounds using α-(phenylthio)isobutyrophenone
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In the presence of catalytic amounts of RhH(PPh3)4 and 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-benzothiazoles, 1,3-benzoxazoles, and benzothiophene reacted with α-(phenylthio) isobutyrophenone giving 2-phenylthio derivatives. Reactive monocyclic heteroaromatics, 1-methyl-1,2,3,4-tetrazole and 2-cyanothiophene were also converted into the 5-phenylthio derivatives. The use of an appropriate phenylthio transfer reagent is crucial for the efficient catalyzed conversion of heteroaromatic C-H bonds into C-S bonds.
- Arisawa, Mieko,Toriyama, Fumihiko,Yamaguchi, Masahiko
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supporting information; experimental part
p. 2344 - 2347
(2011/05/16)
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- Rhodium-catalyzed α-methylthiolation reaction of unactivated ketones using 1,2-diphenyl-2-methylthio-1-ethanone for the methylthio transfer reagent
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In the presence of catalytic amounts of RhH(PPh3)4, 1,2-bis(diphenylphosphino)ethane (dppe), and dimethyl disulfide, ketones without α-activating groups were α-methylthiolated with 1,2-diphenyl-2-methylthio-1-ethanone giving α-methylthio ketones. The reaction of unsymmetrical ketones proceeded at the more substituted carbons. The initial formation of kinetic α-methylthiolated products followed by their rearrangement to thermodynamic products was observed in the reaction of α-phenyl ketones. Aldehydes, phenylacetate, and phenylacetonitrile were also α-methylthiolated under these conditions.
- Arisawa, Mieko,Toriyama, Fumihiko,Yamaguchi, Masahiko
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experimental part
p. 2305 - 2312
(2011/04/22)
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- Synthesis of unsymmetrically substituted benzils via the Friedel-Crafts reaction of arenes with α-chloro-α-(methylthio)acetophenones
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Lewis acid-promoted reactions of arenes with α-chloro-α-(methylthio)acetophenones gave the Friedel-Crafts reaction products, which were then treated with 3 molar eq of cupric chloride in aqueous acetone to afford the unsymmetrically substituted benzils.
- Ishibashi,Matsuoka,Ikeda
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p. 1854 - 1856
(2007/10/02)
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- MILD REACTION OF PUMMERER REARRANGEMENT PRODUCTS WITH AROMATIC COMPOUNDS IN THE PRESENCE OF LEWIS ACIDS. APPLICATION TO THE PREPARATION OF ARYLMETHYLENE KETONES, ARYLACETOESTERS, AND ARYLACETONITRILES.
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Pummerer intermediates generated from precursors (3), (4) and (5) reacted mildly with aromatic compounds in the presence of Lewis acids to give the corresponding sulfides which in turn desulfurized to arylmethylene ketones, arylacetoesters, and arylaceton
- Stamos, Ioannis K.
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p. 477 - 480
(2007/10/02)
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- Introduction of α-(acyl) methylthiomethyl group into the aromatic ring by Friedel-Crafts reaction
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Friedel-Crafts α-(acyl)methylthiomethylations of aromatic compounds with α-ethoxycarbonyl, -acetyl, -benzoyl, and -cyano-α-(methylthio)methyl chlorides are described. The resulted products are easily converted to acylmethylated aromatics such as phenylacetate and phenylacetone by reductive desulfurization.
- Tamura,Shindo,Uenishi,Ishibashi
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p. 2547 - 2548
(2007/10/02)
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